The present invention relates to a process camera for printing pictures of different sizes in the desired display positions on a photosensitive material to obtain a press plate.
Usually, when a book is made by bookbinding, a plurality of pages are printed in both surfaces of a large printing paper, and thus the printing paper is folded to prepare one "section" which usually includes an octavo 16 pages and is the minimum unit for bookbinding. A plurality of sections are binded together to produce a book. The number and arrangement of the pages to be printed on the printing paper depend on the plate sizes, the size of the printing paper, the type and the size of the printer, the printing style, and so forth.
In FIGS. 1 and 2 there are shown both surfaces of an octavo 16 pages of one section of the printed paper 1 wherein a signature or a nigger head 2 and register marks 3 are attached, and wherein page numbers such as 1p-16p and photographing numbers I-VIII, hereinafter mentioned, are shown. The printed paper 1 is obtained in a conventional manner as follows:
(i) Each of the pages is photographed one by one on the film to produce negative plates for one section of one printing paper, and thus the obtained negative plates for the one section are arranged on a base film in the desired positions (for example, as shown in FIGS. 1 and 2). Then, the negative plates arranged on the base film are printed on a photosensitive material by exposing the light thereon, thereby obtaining a press plate. PA1 (ii) The pages for one section of one printing paper are arranged on a base sheet in the desired positions, and the pages arranged on the base sheet are photographed on a film to obtain a large negative plate. Then, the large negative plate is printed on a photosensitive material, thereby obtaining a press plate. PA1 (iii) Each of the pages is photographed one by one on a microfilm in the reduced scale, in advance, and then the necessary pages for the one section of the printing paper are automatically picked up and are projected to a photosensitive material in the desired display positions, thereby obtaining a press plate.
The method (i) is mostly carried out, but this method is performed manually in the most steps. Accordingly, it takes a lot of time and labors and an operational mistake is apt to be happened.
The method (ii) is often practiced and the time and the labors are considerably saved. However, the display of the pages on the base sheet is carried out manually, and hence a mistake is liable to arise. Further, since the pages displayed on the base sheet for one section is photographed altogether by one operation, a large process camera is required.
The method (iii) is effective for saving the labors and materials. However, the reducing and the enlarging photographing steps by optical systems are involved, and thus the quality of the reproduction image is lowered. Further, a costly apparatus is required. Accordingly, this method is less practiced now.
In order to remove these disadvantages of the conventional methods, another process camera has been proposed, as disclosed in Japanese patent application No. 55-153427.
However, in this embodiment, when the page is photographed upside-down with respect to the printing paper, a picture holder having a pair of register pins for positioning the page is rotated through 180 degree. Hence, the construction of the picture holder is complicated and costly, and the rotation of the picture holder requires more time than usual.